Stapedial Prosthesis and Method of Implanting the Same

ABSTRACT

A stapedial prosthesis includes a body defining a bucket and a shaft, and a bail handle coupled to the bucket. The bucket is preferably adjustable in diameter to fit the incus lenticular process. The shaft preferably has a varying diameter, with a central portion of a smaller diameter than a distal portion which aids in depth perception during implantation and reduces mass to permit better sound energy transmission by the prosthesis. The bail handle is preferably spring-loaded and preferably constructed of titanium. The bail handle is preferably coupled to the body without crimping, twisting or welding and preferably biases the incus toward the bucket. A method of implanting a stapedial prosthesis is also provided.

RELATED CASE

This application is a continuation of U.S. Ser. No. 10/666,451, filedSep. 19, 2003, which is hereby incorporated by reference herein in itsentirety.

BACKGROUND

1. Field of Invention

The present invention relates to ossicular prostheses, more particularlyto an improved stapedial prosthesis.

2. State of the Art

Medical Background: Stapes Diseases

Referring to prior art FIGS. 1 and 2, in a normal ear, sound energy,which consists of vibrations of air molecules, is directed by theauricle, or outer ear, through the ear canal to the tympanic membrane.Movements of the tympanic membrane are transferred to the ossicles, orthe ossicular chain of the bones of the middle ear: malleus, incus andstapes. These movements eventually reach the inner ear labyrinth fluidsvia the stapes, which rests in a small groove, commonly called the ovalwindow. The oval window is in intimate contact with the inner earfluids. The movement of the inner ear fluids then stimulates the finesensory organs of the inner ear, which in turn stimulate the auditorynerve, finally transferring the original sound energy to the brain.

Certain pathologies within the middle ear ossicular chain interrupt thetransmission of sound energy and cause hearing loss. When this occurs,re-construction of the ossicular chain, using man-made prostheses, isoften required. Three general conditions of discontinuity exist in whicha prosthesis is appropriate. When the malleus, incus and stapes areabsent, a Total Ossicular Replacement Prosthesis (or TORP) is used. Whenthe stapes is absent but the malleus and incus are present, a PartialOssicular Replacement Prosthesis (or PORP) is used. When the stapesfootplate is fixed due to a condition referred to as otosclerosis, astapes prosthesis is used.

Otosclerosis is one of the most common causes of progressive hearingloss in which there is an abnormal growth of bone in the ear. Whenotosclerosis is present there is an abnormal, microscopic growth of bonein the walls of the middle ear. This abnormal growth impedes theconduction of sound energy from the tympanic membrane to the inner ear.In particular, otosclerosis affects the stapes bone by causing it tobecome frozen in place or “fixed.” Normally the stapes vibrates freelyto allow the transmission of sound energy into the inner ear. When itbecomes fixed to the surrounding bone, it prevents sound waves fromreaching the inner ear fluids, and thus hearing is impaired.

When the amount of otosclerosis at this location is significant, asdetermined by careful hearing tests, surgery has been found to be themost effective method of improving hearing loss caused by thiscondition. This surgery is termed a stapedectomy and serves to restorecontinuity between the incus and inner ear fluids. A stapedectomy issometimes performed in patients who have a congenital abnormality of thestapes or have sustained a fracture of the stapes from traumaticincident. However, the most common indication for a stapedectomy isotosclerosis.

Medical Background: Stapedectomy Surgery Technique

Surgical treatment for otosclerosis has been available for about 45years. The first operation for this disease was the fenestrationprocedure, which required mastoid surgery and an artificial opening inanother part of the inner ear. The attention of surgeons became focusedon the diseased stapes itself and the stapes mobilization procedure wasdeveloped. With the improvement in surgical techniques, the treatment ofchoice became stapedectomy. This procedure was first performed in 1956and has remained the mainstay of treatment for otosclerosis.

The objectives of stapedectomy are: (1) to open the oval window forsound entry into the inner ear labyrinth; (2) to reconstruct aconductive bridge between the incus and the labyrinth; and (3) toaccomplish these goals as efficiently and physiologically compatible aspossible for long-term hearing without complication. To accomplish theseobjectives the stapedectomy is performed through an incision in the earcanal under local or general anesthesia. A flap consisting of canal skinand tympanic membrane is elevated and the posterior superior bonyexternal auditory canal wall is removed, usually by a drill, to exposethe malleus, incus, stapes and chorda tympani (facial nerve). Theossicles are inspected and palpated to establish the precise diagnosisof the conductive hearing loss; that is, the fixation of the stapes andmobility of the malleus and incus are confirmed. The distance betweenthe undersurface of the incus and the stapes footplate is then measuredto determine the prosthesis length.

With care taken to preserve the chorda tympani, the synovial jointbetween the lenticular process of the incus and the head of the stapesis separated (incudostapedial joint). The stapes tendon and one crus(leg) of the stapes is then severed. The arch of the stapes may then beremoved by fracturing the other crus while allowing the stapes footplateto remain in the oval window. An opening is created in the footplate toallow entrance for a stapedial prosthesis. In some cases, the footplateis removed and a vein is grafted to the internal wall of the tympanum tocover the opening and to support the stapes prosthesis. After theopening is made in the footplate, or tissue is placed over the openingmade to the inner ear after removing the footplate, one end of astapedial prosthesis of proper length is posted in the opening while theother end is attached to the incus. The incus is gently palpated toobserve the motion of the stapedial prosthesis. A piece of fat or tissueis applied (obtained, as one example, from a small incision behind theear lobe) in order to seal any hole in the oval window. Finally, theeardrum is folded back into its normal position.

Medical Background: Prior Art Prostheses

A critical part of the stapedectomy procedure is attaching theprosthesis around the lenticular process of the incus due to itsminiature size, typically about 3.5 mm to 6 mm long and 0.4 mm to 0.8 mmdiameter, and its delicate nature. There have been several devicesproposed for the stapedial prosthesis. One class includes those that usea crimping technique. For instance, in U.S. Pat. No. 5,370,689 toCausse, one end of the prosthesis, fabricated of PTFE, is posted in anopening drilled in the exposed footplate, and a split eyelet at theother end must be crimped around the incus. In U.S. Pat. No. 3,711,869to Shea Jr. one end of the prosthesis is placed on a vein graftinvaginated into the oval window, and a split eyelet at the other endmust be forced open by elastic deformation to fit onto the incus.Elastic recovery capacity of the eyelet causes it to restore to itsoriginal form in about 20 minutes and grip the incus firmly. U.S. Pat.No. 3,838,468 to Armstrong discloses a stapedial prosthesis for use incases where the footplate is also removed. A piston is fixed at one endto a vein graft for covering the oval window. A wire of stainless steel,platinum, gold, or like biocompatible material shaped like a shepherd'scrook extending from the other end, is crimped about the lenticularprocess of the incus.

Another type of prosthesis in use is the “bucket-handle prosthesis,”which in comparison to the traditional crimped stapes prosthesisdiscussed above, is reportedly easier to insert (as discussed byRothbaum, et. al in “Task performance in stapedotomy: Comparison betweensurgeons of different experience levels,” Otolaryngol Head Neck Surg.128:71-7 (2003)). Referring to prior art FIGS. 3 and 4, U.S. Pat. No.3,196,462 to Robinson discloses one type of bucket-handle device 10,also termed the bucket-and-bail device, which includes a bucket 12 (alsotermed a well or a socket), a wire bail 14 (handle) at one end forreceiving and securing a portion of the disarticulated lenticularprocess 16 of the incus 18, and a cylindrical shaft 21 portion 20 (orstem or rod) at the other end for engaging the oval window 22, or tissue24 (e.g., a vein graft or fat tissue) that is placed over the openingmade to the inner ear after removing the footplate. The bail 14 isoriented by the surgeon so that its axis of pivotal rotation generallyis horizontal. With the prosthesis 10 in that configuration, the incuslenticular process 16 is positioned in the bucket 12 and the bail 14 isrotated in an upward arc about a fulcrum point on the bucket, past thehorizontal, until the bail contacts the long process of the incus 18. Inthis particular device, only the frictional engagement of the bail 14against the incus 18 holds the bail in place. If the bail should rotatedownwardly, out of range of contact with the incus, the prosthesis maybecome dislodged and extrusion may result. In contrast, with a crimpablewire-crook prosthesis, a short term risk is that the prosthesis willfracture the incus. Additionally, a loose fitting crimpable prosthesismay erode or wear away the incus from irregular loose vibration. Thus,the challenge of stapedial prostheses, whether a bucket-and-bail type ora crimpable type is to secure the prosthesis sufficiently well to theincus to avoid its failing out of position while being careful not tohave a connection to the incus that allows the incus to erode or tofracture.

U.S. Pat. No. 4,292,693 to Shea et. al discloses one means forovercoming the bail securement problem. Referring to prior art FIGS. 5and 6, the stapedial prosthesis 40 of Shea et al. provides a pair of camsurfaces 42 oppositely mounted on the bucket portion 44 which permitsovercenter pivotal movement of the bail 46 in one direction andthereafter prevents overcenter pivotal movement of the bail in theopposite direction. Each of the cam surfaces 42 tapers outwardly fromthe surface of the bucket portion 44 in the direction the overcenterpivotal movement of the bail 46 is permitted, and terminates in aninwardly extending shoulder portion 48 which engages the bail 46 toprevent the overcenter pivotal movement thereof in the oppositedirection.

Currently, these bail handles are constructed from stainless steel.Current attachment methods of the bail handle to the bucket inbail-and-bucket device require that the bucket handle protrude into thebucket of the prosthesis, thus disturbing the incus process as it liesin the bucket, which further creates problems in measuring theprosthesis bucket for a correct fit. During the manufacturing process, athrough-hole 50 is first made completely through the bucket body 44. Thebail 46 is then formed into a generally elongated D-shaped configurationwith ends turned inwardly at right angles. The bail 46 is preferablyformed of a single strand of stainless steel wire with its ends 52, 54joined in abutting relationship as by a weld 56, twisting or crimping.The stainless steel material of the bail 46 is such that one end may bedeformed and inserted completely through the hole 50 so that the weld 56may be made. Thereafter, the weld 56 is pulled into the through-hole 50until it is approximately centered and the deformed portion resumes itsoriginal shape. This securement method results in a variability of sizeand maneuverability in the bail handle, which further complicates thesurgical insertion of the device.

It is readily apparent that great care and skill are required to securethese and similar prostheses to the lenticular process of the incus. Theminute size of the prostheses also makes them extremely difficult tomanipulate into proper position for tightening around the incus, evenwith state-of-the-art microsurgical instrumentation. This is made moredifficult as during the stapedectomy surgery, the view at the prosthesisinsertion site is restricted.

As mentioned above, measurement and selection of the prosthesis, whichis affected by current manufacturing processes, is critical for properfunctionality. Once in place, if the prosthesis is not tightenedsufficiently about the incus, fluctuating hearing loss, dizziness, orextrusion of the prosthesis may occur. If it is too tight, necrosis ofthe incus may occur. In either case, the securement method in itself maycause trauma to the delicate middle ear structures, including fractureor subluxation (dislocation) of the incus.

Therefore, from the above, it can be appreciated that there is a needfor an improved bucket-handle prosthesis, particularly with respect tomanufacturing repeatability of the bail handle and easier and moreproficient attachment to the incus process.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an improvedbucket-handle stapedial prosthesis.

It is another object of the invention to provide a stapedial prosthesiswhich facilitates manufacture, assembly and surgical implantation.

It is also an object of the invention to provide a visual cue for thesurgeon that aids in depth perception while operating in the middle eararea.

It is an additional object of the invention to provide a stapedialprosthesis that better conforms to a patient's anatomy.

It is a further object of the invention to provide a stapedialprosthesis that is adaptable in size for the incus.

It is yet another object of the invention to provide a stapedialprosthesis that provides better transmission of sound energy, and thusbetter hearing results.

It is yet an additional object of the invention to provide a stapedialprosthesis that does not cause artifacts on MRI images.

In accord with these objects, a stapedial prosthesis is provided andincludes a bucket body, a bail handle, and a shaft. In accord with onepreferred aspect of the invention, the bucket body preferably includes aplurality of slots positioned in the bucket wall which allow selectedsegments of the bucket wall to bend inwardly or outwardly. When thesewall segments are manipulated by the surgeon, the bucket can adapt to avariety of incus process diameters.

In accord with a second preferred aspect of the invention, theprosthesis overcomes certain problems in the prior art by constructingthe bail handle from a resilient material, such as titanium. By usingthe spring-like tension of titanium, the bail handle is secured in twoholes within the wall of bucket body in such a way that allows completefreedom and unobstruction to the incus process as it lies in the bucket.The spring tension of the bail handle causes the handle to remainaffixed to the bucket without welding, twisting or crimping, and thehandle does not extend all the way through the body as in prior artdevices. Since there is no welding, twisting or crimping, there is amore uniform fit and movement of the bail handle when attached to thebucket, thus aiding further in the installation of the prosthesis.Furthermore, the handle, once manipulated by the surgeon, remains in afixed relation relative to the bucket. Additionally, the use of titaniumprovides less imaging artifact in magnetic resonance imaging situationsas titanium is a more MRI transparent material than stainless steel.

In accord with a third preferred aspect of the invention, visualizationof the prosthesis during implantation is aided by providing a shaftportion of the device with a central portion having a relative smallerdiameter than a distal end portion which attaches to or adjacent theanatomical oval window. This change in dimension provides a visual cuefor the surgeon as the surgeon places the prosthesis into the openingmade in the oval window. The smaller diameter central portion of theshaft also helps to reduce the mass of the device thus aiding in thesound energy transmission from the tympanic membrane to the inner ear.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Prior art FIG. 1 is a cross-sectional profile of the human ear;

Prior art FIG. 2 is a cross-sectional profile of the human ear showingthe ossicular chain;

Prior art FIG. 3 is a perspective view of a prior art bucket-handlestapedial prosthesis;

Prior art FIG. 4 is a side elevation view of the prior art stapedialprosthesis of FIG. 3, shown implanted between the incus and the ovalwindow;

Prior art FIG. 5 is a perspective view of another prior artbucket-handle stapedial prosthesis;

Prior art FIG. 6 is a cross-sectional profile of the prior art stapedialprosthesis of FIG. 5, showing the weld joint of the wire bail; 11

FIG. 7 is an exploded view of a bucket-handle stapedial prosthesisaccording to the present invention;

FIG. 8 is a front elevation view of the stapedial 16 prosthesis of FIG.7;

FIG. 9 is a rear elevation of the stapedial prosthesis of FIG. 7;

FIG. 10 is a right side elevation view of the stapedial prosthesis ofFIG. 7;

FIG. 11 is a perspective view of a first portion of the stapedialprosthesis implantation procedure; and

FIG. 12 is a perspective view of a second portion of the stapedialprosthesis implantation procedure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 7 through 10, a preferred embodiment of a stapedialprosthesis 100 includes a body 102 and a bail handle 104. The body 102is preferably constructed from commercially pure Grade 2 titanium, andis further defined by a closed-bottom bowl shaped cavity, termed thebucket 106 (or well), which tapers down to a shaft 108 (also termed astem or a rod). The bucket 106 of the body 102 is sized to accept thelong process and lenticular process of the incus. The body 102 of theprosthesis 100 preferably defines four holes 110, 112, 114, 116, eachdesigned for a specific purpose as now described. The twodiametrically-opposed holes 110, 112 near the bottom of the bucket 106are receptacles (bail insert openings) for receiving ends 118, 120 ofthe bail handle 104, described below. The hole 114 located at the rearof the bucket 106 near the rim 142 is intended for positioning theprosthesis 100. That is, a surgeon can insert a pick 200 and turn theprosthesis 100 to achieve an optimum fit for each patient, as describedin more detail below with respect to FIG. 11. The hole 116 near thedistal end of the shaft 108 is optional, and where provided allows fortissue in-growth and further stabilization of the device, as the distalend of the shaft end engages the oval window, or graft tissue that isplaced over the fenestration made to the inner ear after removing theanatomical footplate, as described in detail below.

According to one preferred aspect of the prosthesis 100, the diameter ofthe bucket 106 is adjustable. A preferred mechanism for adjusting thediameter includes a plurality of slots 128 provided in the wall 130 ofthe bucket 106 (four slots being shown, although more or fewer could beused) which define individual wall segments 132 (FIG. 10). Each slot 128is preferably about 0.1-mm wide, and defines an arc about thecircumference of the bucket 106 which is substantially smaller than thattraversed by each wall segment 132, e.g., by a factor of four or more.The slots 128 permit the segments 132 of the bucket wall 130 to be bentinwardly or outwardly. When the wall segments 132 are manipulated by thesurgeon, the bucket can adapt to a variety of incus process diameters.Note that the slots 128 preferably extend down the side of the bucket106 until just above the bail insert openings 110, 112, thus notaffecting the bail-to-bucket connection, described below.

The bucket 106 optionally has an incus notch 140 in the rim 142 of thebucket wall 130. A prosthesis with an incus notch 140 in the bucket 106is generally selected by the surgeon when a determination is made thatthe incus is too eroded or too short for a closed (non-notched) bucket.As such, alternatively, a closed bucket can be provided to theprosthesis for use with an incus having good form. In such anembodiment, the front and rear views of the bucket 106 would generallybe as shown in FIG. 9, with manipulation hole 114 optionally not beingprovided at the front of the bucket.

According to another preferred aspect of the prosthesis 100, the bailhandle 104 is a generally U-shaped or smoothly-arced structure. Inaddition, the handle is preferably constructed from titanium, and morepreferably 0.125-mm (0.005″) diameter commercially-pure Grade 4titanium. The handle 104 has end portions 118, 120 which are inwardlydirected toward each other and define a space therebetween that issmaller than the outer diameter of the bucket 106 at the bail insertopenings 110, 112.

The handle 104 is designed to be freely manipulated by the surgeonrelative to the bucket 106 (rotating about the openings 110, 112) sothat it can be flipped up and over the incus once the incus lenticularprocess has been placed in the bucket 106 of the prosthesis 100. Thehandle 104 acts as a means for stabilizing the prosthesis relative tothe incus process by holding the incus in place, and further preventsthe prosthesis from slipping off of the incus. The properties oftitanium, as the preferred material for the handle, contribute inseveral areas with respect to the prosthesis 100. Since titanium hasbetter spring-like mechanical properties than stainless steel, thischaracteristic can be used to hold the handle 104 to the bucket 106 ofthe prosthesis, e.g., the spring-like tension forces the ends 118, 120of the handle 104 into the bail insert openings 110, 112, thus holdingthe handle 104 to the bucket 106 without the need for welding, twistingor crimping. The ends 118, 120 of the bail handle 104 are not coupled toeach other, do not contact each other, and do not pass each other withinthe bucket 106. And once manipulated by the surgeon, the bail handle 104under tension remains in a fixed relationship relative to the bucket 106without concern of unintended movement which may otherwise result inundesirable loosening of the incus relative to the prosthesis 100.

With respect to manufacturing and assembly advantages, because thehandle 104 is formed prior to assembly, and considering the handlematerial is preferably titanium, the handle has a relatively low massand presents a more uniform, repeatable shape. During the assemblyprocess, the ends 118, 120 of the handle 104 are slightly spread apart,manipulated about the bucket 106 and then released into the bail insertopenings 110, 112 of the bucket 106 of the prosthesis, a much simplermethod than current approaches. Due to this simplified assemblytechnique, manufactured units are more uniform. Furthermore, the bailhandle 104 does not protrude into the bucket 106, and thus the cavity ofthe bucket 106 remains open permitting a more complete fit of the incusprocess within the bucket. Referring specifically to FIG. 7, accordingto another preferred aspect of the prosthesis, the shaft 108 of thestapedial prosthesis 100 has a central section 160 and a distal section162 of different diameters. The bucket 106 tapers down to the centralsection 160 of the shaft 108 to a diameter of approximately 0.3-mm. Theshaft 108 continues at this diameter until reaching the distal section162 where it enlarges in diameter, preferably to approximately 0.4-mm to0.8-mm. This varying diameter provides at least two advantages. First,the mass of the prosthesis 100 is reduced, which in turn aids in theconduction of sound, and thus the patient's hearing. Second, a visualcue is provided to the surgeon of the location of the distal section 162of the prosthesis within the middle ear area.

Referring now to FIGS. 11 and 12, the implantation of the prosthesis 100will now be described, wherein the prosthesis is provided with the incusnotch 140. Implantation using a closed bucket (non-notched) designproceeds in a similar manner.

Referring specifically to FIG. 11, after the surgeon removes the stapesand performs the necessary steps preparatory to implantation of thestapedial prosthesis of the present invention, e.g., creating astapedotomy opening in the footplate to allow entrance for the stapedialprosthesis, or covering the oval window 22 with a tissue graft 24 of thesurgeon's choice, the prosthesis 100 is inserted into position usingforceps. In so doing, the distal section 162 of the prosthesis is placedagainst the graft tissue 24. The prosthesis can be manipulated into adesired orientation by engaging the upper opening 114 of the prosthesis100 with a right angle pick tool 200 and manipulating the prosthesistherewith. In proper orientation, the incus notch 140 will be located atthe top of the lenticular process 16 of the incus 18, with a portion ofthe lenticular process inserted into the incus notch 140 of the bucket106. During the initial step of the insertion procedure, the bail handle104 is rotated to the side of the bucket 106 having the upper opening114 for the positioning tool (i.e., opposite the notch 140). The surgeonthen gently moves the incus process (in the direction of arrow 202),rotates the prosthesis (in the direction of arrow 204), and sets thelenticular process 16 into the bucket 106. 6

Where the bucket wall 130 is segmented, the surgeon has two options foradapting the size of the bucket 106 to the size of the incus process 16.In a first approach, after placing the incus lenticular process 16 intothe bucket 106, the surgeon bends one or more of the wall segments 132(FIG. 10) until just touching the process 16, thus gripping the incus18. At this point the surgeon rotates the bail handle 104 to furtherhold the incus relative to the prosthesis, preferably as follows.Referring to FIG. 12, the surgeon rotates and pulls the bail handle 104upward and outward so that the bail handle 104 passes through a planecontaining both the bail handle and the longitudinal axis A of theprosthesis. The surgeon continues the upward and outward rotation of thebail handle 104 until it is in proper position about the long process ofthe incus 18. As the surgeon releases the spring-loaded bail 104, thetension in the bail handle 104 may aid in holding the incus process 16within the bucket 106.

In a second approach, the surgeon would place the incus lenticularprocess 16 into the bucket 106, rotate the bail 104 as described above,then bend one or more wall segments 132 (FIG. 10) until just touchingthe process, thus gripping the incus 18 further.

As yet another alternative, the wall segments 132 may be left in theirmanufactured configuration, and the force of the bail handle 104 aloneis used to hold the incus process 16 relative to the prosthesis 100.

With respect to post-operative considerations, the preferablyall-titanium prosthesis has excellent bio-compatibility and, due to itsnon-magnetic nature, has little effect on magnetic resonance imaging(e.g., very low MRI image artifacts).

The device may be constructed in a range of dimensions with respect tobucket diameters, shaft diameters, and lengths. In this manner, a devicecan be selected by the surgeon that corresponds to the anatomicalfeatures of a patient. Exemplar dimensions follow. The overall length ofthe body 102 (bucket 106 and shaft 108) is 3.5-mm to 9.0-mm. The bucket106 has a length of 0.8-mm to 1.3-mm, a diameter of 0.85-mm to 1.5-mm,and a wall thickness of 0.1525-mm. One preferred inner diameter of thebucket 106 is 0.965-mm and one preferred outer diameter of the bucket is1.27-mm. Each of the four holes 110, 112, 114, 116 has a diameter ofapproximately 0.150-mm. The bail handle 104 has a length of 2.13-mm, awidth (across parallel shaft portions 150, 152 of FIG. 7) of 1.49-mm,and a cross-sectional diameter of 0.125-mm. The shaft 108 has a lengthof 2.7-mm to 7.7-mm, and a diameter of 0.4-mm to 0.8-mm. Where the shafthas the preferred varying diameter, the central section 160 preferablyhas a length of 2.4-mm to 6.7-mm and a diameter of 0.3-mm, and thedistal section preferably has a length of 0.3-mm to 1.0-mm and adiameter of 0.4-mm to 0.8-mm.

There have been described and illustrated herein embodiments of astapedial prosthesis and methods of implantation of the same. Whileparticular embodiments of the invention have been described, it is notintended that the invention be limited thereto, as it is intended thatthe invention be as broad in scope as the art will allow and that thespecification be read likewise. Thus, while several preferred aspects ofthe invention have been described with respect to the figures, it isintended that each of the preferred aspect and other aspects of theinvention may be implemented independently or in combination with one ormore other aspects of the invention. That is, each of the segmentedbucket, the spring-tensioned bail handle, and the shaft with reduceddiameter central portion may be implemented in an otherwise conventionalstapedial prosthesis with or without the other preferred aspects. Inaddition, while particular exemplar dimensions have been disclosed, itis understood that other dimensions can be provided to the elements ofthe prosthesis provided such dimensions allow the prosthesis to be usedas a stapedial prosthesis. Also, while titanium, and more particularlypreferred specific grades of titanium, have been disclosed, it isappreciated that the preferred aspects of the invention may beimplemented in materials other than titanium. It will therefore beappreciated by those skilled in the art that yet other modificationscould be made to the provided invention without deviating from itsspirit and scope as claimed.

1. A stapedial prosthesis sized to be implanted as a replacement for thestapes between the incus and the oval window of the middle ear,comprising: a) a bucket sized to at least partially receive a portion ofthe incus, said bucket including holes for receiving a handle; b) ashaft coupled to said bucket and having a length sufficient to extendfrom the incus to the oval window; and c) a handle including endsspring-loaded into said bucket so as to cause said handle to remain in afixed position relative to said bucket unless manipulated.
 2. Astapedial prosthesis according to claim 1, wherein: said handle does notextend all the way through said bucket.
 3. A stapedial prosthesisaccording to claim 2, wherein: said handle is coupled to said bucketwithout welding, twisting or crimping.
 4. A stapedial prosthesisaccording to claim 2, wherein: said handle is spring loaded against anouter surface of said bucket.
 5. A stapedial prosthesis according toclaim 1, wherein: said handle is constructed of titanium.
 6. A stapedialprosthesis according to claim 2, wherein: said handle is U-shaped.
 7. Astapedial prosthesis according to claim 1, wherein: said bucket includesa rim and a notch in said rim.
 8. A stapedial prosthesis according toclaim 1, wherein: said bucket has a wall with a plurality of slotsdefining wall segments, and said wall segments are manipulatable by asurgeon to adjust an inner dimension of said bucket.
 9. A stapedialprosthesis sized to be implanted as a replacement for the stapes betweenthe incus and the oval window of the middle ear, comprising: a) a buckethaving an initial size that at least partially receives a portion of anincus and having a wall with a plurality of slots defining wallsegments, said bucket being reducible in size by surgeon manipulation ofat least one of said wall segments so as to contact the portion of theincus positioned therein so as to grip the incus after the incus is atleast partially received therein; b) a shaft having a length sufficientto extend from the incus to the oval window; and c) a bail handlecoupled to said bucket.
 10. A stapedial prosthesis according to claim 9,wherein: said slots are approximately 0.1-mm wide.
 11. A stapedialprosthesis according to claim 9, wherein: said slots define arcs about acircumference of the bucket which are substantially smaller than arcstraversed by the wall segments defined by the slots.
 12. A stapedialprosthesis according to claim 9, wherein: said arcs defined by saidslots are smaller than said arcs defined by said wall segments by afactor of at least four.
 13. A stapedial prosthesis according to claim9, wherein: said bucket has a closed bottom portion.
 14. A stapedialprosthesis sized to be implanted as a replacement for the stapes betweenthe incus and the oval window of the middle ear, comprising: a) a bodydefining a bucket for at least a portion of the incus; b) a rotatablebail handle coupled to said bucket; and a) a shaft having a lengthsufficient to extend from a portion of the incus to the oval window,said shaft having a central portion and first and second end portions,said central portion having a diameter of approximately 0.3-mm, saidfirst end portion having a diameter of approximately 0.4-mm to 0.8-mm,and said second end portion being coupled to said bucket.
 15. Astapedial prosthesis according to claim 14, wherein: said first endportion includes structure for tissue ingrowth.
 16. A stapedialprosthesis according to claim 14, wherein: said first end portion has alength not exceeding 1-mm.
 17. A stapedial prosthesis according to claim14, wherein: said first end portion has a length greater than 0.3-mm.18. A stapedial prosthesis according to claim 14, wherein: said centralportion has a length at least approximately 2.4 times a length of saidfirst end.
 19. A stapedial prosthesis according to claim 14, wherein:said body, said bail and said shaft are all made of titanium.
 20. Astapedial prosthesis sized to be implanted as a replacement for thestapes between the incus and the oval window of the middle ear,comprising: a) a bucket with a cavity sized to at least partiallyreceive a portion of an incus and having a radial center, said bucketincluding a wall with openings therein; b) a shaft coupled to saidbucket, said shaft having a length sufficient to extend from the incusto the oval window; and c) a handle element coupled to said bucket atsaid openings, said handle element having ends which are detached fromeach other but located within the body, but do not extend to or pastsaid radial center of said body.
 21. A stapedial prosthesis according toclaim 20, wherein: said bucket, said shaft and said handle element areall made from titanium.
 22. A stapedial prosthesis sized to be implantedas a replacement for the stapes between the incus and the oval window ofthe middle ear, comprising: a) a bucket with a cavity sized to at leastpartially receive a portion of an incus; b) a shaft coupled to saidbucket and having a length sufficient to extend from the incus to theoval window; and c) a handle element having first and second ends, saidhandle element coupled to said bucket, and first and second ends (i)each being uncoupled from the other, (ii) each being located within saidbody, and (iii) each not passing the other within said bucket.
 23. Astapedial prosthesis according to claim 22, wherein: said bucket, saidshaft and said handle element are all made from titanium.